4"

The 4" Wilkins 350 is a double check valve assembly began production in 1998 and is still currently being produced. The body is constructed of epoxy coated ductile iron. Check assemblies are a plastic cam check design and springs are self contained. Spring tension does not need to be released to replace rubber discs. Retainer clips hold the checks in place. The 350 uses a single victaulic clamp style cover. In 2004, the 350A model was introduced. The "A" used grooved connections between the body and gate valves. Please be sure which model you have because some repair parts are different. In 2010, all bronze parts (test cocks, bulkhead fittings, ect.) were transitioned to lead free bronze to adhere to new codes. No special tools are required for servicing.

The 4" Wilkins 350A is a double check valve assembly began production in 2004 and is still currently being produced. The body is constructed of epoxy coated ductile iron. Check assemblies are a plastic cam check design and springs are self contained. Spring tension does not need to be released to replace rubber discs. Retainer clips hold the checks in place. The 350A uses a single victaulic clamp style cover. The 350A uses grooved connections between the body and gate valves while the 350 is flanged. Please be sure which model you have because some repair parts are different. In 2010, all bronze parts (test cocks, bulkhead fittings, ect.) were transitioned to lead free bronze to adhere to new codes. No special tools are required for servicing.

The 4" Wilkins 350DA is a double check detector assembly began production in 1998 and is still currently being produced. The body is constructed of epoxy coated ductile iron. Check assemblies are a plastic cam check design and springs are self contained. Spring tension does not need to be released to replace rubber discs. Retainer clips hold the checks in place. The 350 uses a single victaulic clamp style cover. The bypass uses a 3/4" Wilkins 950XL backflow preventer and a standard 5/8 X 3/4" Water meter. In 2004, the 350ADA model was introduced. The "A" used grooved connections between the body and gate valves. Please be sure which model you have because some repair parts are different. In 2010, all bronze parts (test cocks, bulkhead fittings, ect.) were transitioned to lead free bronze to adhere to new codes. No special tools are required for servicing.

The 4" Wilkins 350ADA is a double check detector assembly began production in 2004 and is still currently being produced. The body is constructed of epoxy coated ductile iron. Check assemblies are a plastic cam check design and springs are self contained. Spring tension does not need to be released to replace rubber discs. Retainer clips hold the checks in place. The 350ADA uses a single victaulic clamp style cover. The 350ADA uses grooved connections between the body and gate valves while the 350DA is flanged. Please be sure which model you have because some repair parts are different. Bypass device will be a 3/4" Wilkins 950XLD. In 2010, all bronze parts (test cocks, bulkhead fittings, ect.) were transitioned to lead free bronze to adhere to new codes. No special tools are required for servicing.

The 4" Wilkins 350AST is a double check valve assembly began production in 2011 and is still currently being produced. The body is constructed of stainless steel. Check assemblies are a plastic cam check design and springs are self contained. Spring tension does not need to be released to replace rubber discs. Retainer clips hold the checks in place. The 350AST uses a single victaulic clamp style cover. The 350AST uses grooved connections between the body and gate valves. No special tools are required for servicing.

The 4" Wilkins 350ASTDA is a double check detector assembly began production in 2011 and is still currently being produced. The body is constructed of stainless steel. Check assemblies are a plastic cam check design and springs are self contained. Spring tension does not need to be released to replace rubber discs. Retainer clips hold the checks in place. The 350AST uses a single victaulic clamp style cover. The 350AST uses grooved connections between the body and gate valves. The bypass device is a 3/4" 950XL or 3/4" 950XLT2. No special tools are required for servicing.

The 4" Wilkins 375 Reduced Pressure Zone began production in 1998 and is still currently in production. Epoxy coated cast iron body has a single victaulic style cover houses both plastic cam checks and a plunger style bronze relief valve hangs below. An external sensing line pressurizes the diaphragm. Self contained cam checks are held in place by retainers. Use caution when servicing as retainers rings often break. No special tools are required for servicing.

The 4" Wilkins 375A Reduced Pressure Zone began production in 2004 and is still currently in production. The 375A uses grooved fittings between the backflow and valves. Epoxy coated cast iron body has a single victaulic style cover houses both plastic cam checks and a plunger style bronze relief valve hangs below. An external sensing line pressurizes the diaphragm. Self contained cam checks are held in place by plastic retaining rings. Use caution when servicing as retainer rings often snap. No special tools are required for servicing.

The 4" Wilkins 375DA Reduced Pressure Detector Assembly began production in 1999 and is still currently in production. Epoxy coated cast iron body has a single victaulic style cover houses both plastic cam checks and a plunger style bronze relief valve hangs below. An external sensing line pressurizes the diaphragm. Self contained cam checks are held in place by plastic retaining rings. Use caution when servicing as retainer rings often snap. Bypass valve shall be 3/4" 975XLD. No special tools are required for servicing.

The 4" Wilkins 375ADA Reduced Pressure Detector Assembly began production in 2004 and is still currently in production. The 375ADA uses grooved fittings between the backflow and valves. Epoxy coated cast iron body has a single victaulic style cover houses both plastic cam checks and a plunger style bronze relief valve hangs below. An external sensing line pressurizes the diaphragm. Self contained cam checks are held in place by plastic retaining rings. Use caution when servicing as retainer rings often snap. Bypass valve shall be 3/4" 975XLD. No special tools are required for servicing.

The 4" Wilkins 375AST Reduced Pressure Zone began production in 2011 and is still currently in production. The 375AST uses grooved fittings between the backflow and valves. Stainless steel body has a single victaulic style cover houses both plastic cam checks and a plunger style bronze relief valve hangs below. An external sensing line pressurizes the diaphragm. Self contained cam checks are held in place by plastic retaining rings. Use caution when servicing as retainer rings often snap. No special tools are required for servicing.

The 4" Wilkins 375ASTDA Reduced Pressure Detector Assembly began production in 2011 and is still currently in production. The 375AST uses grooved fittings between the backflow and valves. Stainless steel body has a single victaulic style cover houses both plastic cam checks and a plunger style bronze relief valve hangs below. An external sensing line pressurizes the diaphragm. Self contained cam checks are held in place by plastic retaining rings. Use caution when servicing as retainer rings often snap. The bypass device shall be a 3/4" Wilkins 975XL. No special tools are required for servicing.

The 4" Wilkins 450 is a double check valve assembly began production in 1998 and is still currently being produced. The body is constructed of epoxy coated ductile iron and is an "N" pattern device. Configuration can be adjusted for vertical mounting or N" shape. Check assemblies are a plastic cam check design and springs are self contained. Spring tension does not need to be released to replace rubber discs. Retainer clips hold the checks in place. The 450 uses a single victaulic clamp style cover. In 2010, all bronze parts (test cocks, bulkhead fittings, ect.) were transitioned to lead free bronze to adhere to new codes. No special tools are required for servicing.

The 4" Wilkins 450DA is a double check detector assembly that began production in 1999 and is still currently being produced. The body is constructed of epoxy coated ductile iron and is an "N" pattern device. Configuration can be adjusted for vertical mounting or N" shape. Check assemblies are a plastic cam check design and springs are self contained. Spring tension does not need to be released to replace rubber discs. Retainer clips hold the checks in place. The 450 uses a single victaulic clamp style cover. In 2010, all bronze parts (test cocks, bulkhead fittings, ect.) were transitioned to lead free bronze to adhere to new codes. Bypass assembly shall be a 3/4" Wilkins 975XL. No special tools are required for servicing.

The 4" Wilkins 550 Double Check Valve backflow preventer was introduced in 1975 under the Richwell Model DC name. Approximately 1978 it was sold to the Neptune Meter Company. The Neptune Company changed the model to 550 and produced it until 1984. Wilkins bought the rights to the device in 1984 and it was discontinued in 1995. The body was made of epoxy coated cast iron and features replacable seats. Check assemblies were self contained. Hard parts have been discontinued for the Model 550 and rubber parts are the only avilable service parts. No special tools are required for servicing.

The 4" Wilkins 575 Reduced Pressure Zone backflow preventer was introduced in 1975 under the Richwell Model DC name. Approximately 1978 it was sold to the Neptune Meter Company. The Neptune Company changed the model to 575 and produced it until 1984. Wilkins bought the rights to the device in 1984 and it was discontinued in 1995. The body was made of epoxy coated cast iron and features replacable seats. Check assemblies are self contained. Check assemblies were not self contained and covers had spring tension against them. The relief valve is attached to the body by a bolted flange and uses an external sensing line. The relief valve seat is replacable. Hard parts have been discontinued for the Model 575 and rubber parts are the only avilable service parts. No special tools are required for servicing.

The 4" Wilkins 950 Double Check Valve Assembly was introduced in 1990 and was discontinued in 2004. The 950 is an epoxy coated cast iron, two cover design. The checks are a bronze poppet style and are self contained. Seats are bronze and are replacable. No special tools are required to service.

The 4" Wilkins 975 Reduced Pressure Zone backflow preventer was introduced in 1990 and was discontinued in 2004. The body was constructed of fused epoxy coated cast iron with a bronze bodied relief valve. Check assemblies were poppet style with self contained springs. Check seats were bronze construction and replaceable. Relief valve is a modular style with a self contained spring. Stainless steel relief seat threads into the body and is replaceable. An external sensing line pressurizes the relief valve. No special tools are required for servicing.

The 4" Wilkins 975DA Reduced Pressure Detector Assembly was introduced in 1993 and was discontinued in 2004. The body was constructed of fused epoxy coated cast iron with a bronze bodied relief valve. Check assemblies were poppet style with self contained springs. Check seats were bronze construction and replaceable. Relief valve is a modular style with a self contained spring. Stainless steel relief seat threads into the body and is replaceable. An external sensing line pressurizes the relief valve. The bypass device shall be a 3/4" Wilkins 975 or 3/4" Wilkins 975XL No special tools are required for servicing.